The black community in the United States explodes in the wake of continuous cases of police brutality.

National Guard troops, in their over-the-top protective armor, patrolling the desolate streets of Baltimore, streets filled with debris, trash and the ashes of bonfires: These images could be the setting for any popular apocalyptic TV series. Unfortunately, they are testament to the grave social problem currently facing the United States.

The violent disturbances and looting that took place in Baltimore (a little less than 40 miles from the U.S. capital) in the early hours of yesterday morning are another serious warning that the black community feels a dangerous frustration after suffering a string of incidents of police violence. This time, the collapse of social harmony was triggered by the death of 25-year-old Freddie Gray. Gray was arrested and put in the back of a police van, from which he emerged unconscious 45 minutes later, the result of an injury that broke his spine. He died a week later.

What has happened – in this case and over the last three years – is incompatible with the Constitution and should push both federal and local U.S. authorities to consider the immediate suspension of certain detention procedures (such as the one in New York in December that resulted in the asphyxiation of Eric Garner, 43, also black) or of the use of weaponry appropriate for an army but not for a police force. Shooting an unarmed man in the back (as happened in the case of Walter Scott – black, 50 years old – a few days ago in South Carolina) should also be severely punished. There have been various stories, with similar endings, in Florida, Ohio, Missouri, Illinois, South Carolina …

It is a profound problem, with both new and old issues. Baltimore’s mayor is black, as is its police commissioner. This did not stop – and couldn’t have stopped – the conflicts that have so far resulted in 15 policemen getting injured, the deployment of troops onto the streets and a nighttime curfew starting last night.

There is an urgent need to curb the immediate cause of this uneasiness – police brutality. Then it is necessary to make great efforts toward confronting a reality that remains hidden, but frequently reappears, that should not be tolerated and that constitutes a serious threat to social harmony in the United States.